STMicroelectronics TSU111IQ1T

Overview

TSU111IQ1T from STMicroelectronics is a single-channel nanopower CMOS operational amplifier designed for ultra-low-power sensor signal conditioning in battery-constrained systems. It delivers 900 nA typical supply current, 150 µV max input offset voltage at 25 °C, rail-to-rail input/output operation across 1.5–5.5 V supply, and 3.6 µVpp low-frequency noise (0.1–10 Hz), enabling precision gas sensing and energy-harvesting interfaces.

For engineers reviewing the TSU111IQ1T datasheet, TSU111IQ1T pinout, TSU111IQ1T application, or TSU111IQ1T equivalent, this op-amp is selected for sub-µA current budgeting, high-impedance electrochemical sensor interfacing, long-life coin-cell operation (e.g., CR2032), and low-noise DC-coupled amplification where offset drift and EMI robustness are critical.

Technical Context

The TSU111IQ1T employs complementary PMOS/NMOS input pairs to achieve true rail-to-rail input common-mode range (VCC− −0.1 V to VCC+ +0.1 V) without phase reversal. Its 11.5 kHz gain bandwidth product and 2.7 V/ms slew rate support stable closed-loop operation with capacitive loads up to 100 pF when properly compensated.

It features MOSFET inputs with ≤10 pA bias current at 25 °C-critical for trans-impedance amplifier configurations with high-impedance sensors-and integrates on-die ESD protection rated to 4 kV HBM, requiring external series resistors if input voltages exceed supply rails.

Key Specifications

Pinout & Package

TSU111IQ1T is housed in a 5-pin SC70 package (2.0 × 1.25 mm), optimized for space-constrained portable designs. The exposed pad is not electrically connected and may be left floating or tied to VCC− for thermal enhancement.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar nanopower operational amplifier applications.

Compared with TSU111IQ1T, TSU101IYLT trades bandwidth and offset for lower current, while TSZ121ILT sacrifices nanopower efficiency for precision and speed-making TSU111IQ1T the optimal balance for gas sensing and energy harvesting where both sub-µA draw and <200 µV offset are mandatory.

Availability

TSU111IQ1T is available at Aetrix Electronics and suitable for gas detection systems, PIR-based security alarms, energy-harvesting wearables, and ultra-long-life battery current monitoring requiring stable component supply across industrial temperature ranges and extended production lifecycles.

Supply support for TSU111IQ1T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, delivering intelligent power, sensing, and control solutions for automotive, industrial, and consumer markets.

The TSU11x family is part of ST's nanopower precision op-amp product line, engineered specifically for battery-operated sensor nodes where decades-long operation, rail-to-rail functionality, and uncalibrated accuracy are non-negotiable design requirements.

FAQ

What is the maximum capacitive load the TSU111IQ1T can drive stably?

The TSU111IQ1T maintains phase margin ≥60° with up to 100 pF capacitive load when configured with appropriate feedback resistance (≥100 kΩ) and a 10 nF local decoupling capacitor. For loads >100 pF, an isolation resistor (R_iso) between output and capacitance is required per Figure 30 in DS11846 to prevent peaking or oscillation.

Can TSU111IQ1T operate from a 1.2 V supply?

No. The absolute minimum supply voltage is 1.5 V per Table 1 and Table 2 of DS11846. Operation below 1.5 V risks undefined behavior, including failure to meet specified offset, bandwidth, or rail-to-rail output swing. For sub-1.5 V systems, consider ST's TSX561 or alternative low-V_CC op-amps.

Is the NC pin on TSU111IQ1T electrically isolated?

Yes. Pin 2 (NC) is internally unconnected and must remain unpopulated or floating-no trace, solder, or test point should contact it. Connecting it risks parasitic coupling, increased leakage, or ESD path disruption, especially in high-impedance sensor layouts.

How does the TSU111IQ1T handle input overvoltage beyond the supply rails?

Its ESD diodes clamp inputs to VCC+ and VCC−, but sustained current >10 mA (per Table 1) will cause damage. Always use series input resistors (≥10 kΩ) when signals may exceed rails-especially in noisy industrial or automotive environments-to limit diode conduction and protect internal circuitry.